* Get an OperationalString GraphNode
*/
GraphNode getOpStringNode(final String name) {
GraphNode opStringNode = null;
for(Iterator it=g.neighbors(root); it.hasNext();) {
Tuple t = (Tuple)it.next();
Object o = t.get(Constants.USER_OBJECT);
if(o!=null && o instanceof GraphNode) {
GraphNode node = (GraphNode)o;
if(node.getOpString()!=null &&
node.getOpStringName().equals(name)) {
opStringNode = node;